Department of Radiology, Martin-Luther-University Halle-Wittenberg, Halle, Germany.
Skeletal Radiol. 2011 Apr;40(4):439-46. doi: 10.1007/s00256-010-1018-x. Epub 2010 Aug 10.
The aim of the present study was to analyse magnetic resonance findings of intramuscular metastases (IM) in a relatively large series.
From January 2000 to January 2010, 28 patients (207 metastases) were retrospectively identified in the radiological database of the Martin-Luther-University. Several different scanning protocols were used depending on the localisation of IM. In 12 patients diffusion-weighted (DW) images were obtained with a multi-shot SE-EPI sequence. Apparent diffusion coefficient (ADC) maps were also calculated. Furthermore, fusion images were manually generated between the DW and half-Fourier acquisition single-shot turbo spin echo (HASTE) images.
On T2-weighted images, 97% of the recognised IM were hyperintense in comparison to unaffected musculature, and 3% were mixed iso- to hyperintense. On T1-weighted images most IM (91%) were homogeneously isointense in comparison to muscle tissue, whereas 4% were hypointense, and 5% lightly hyperintense. ADC maps were calculated for 91 metastases ranging from 0.99 to 4.00 mm(2)s(-1) (mean value 1.99 ± 0.66). ADC values of low (<1.5) signal intensity (SI) were identified in 26%, moderate SI (from 1.5 to 3.0) in 68%, and high SI (>3.0) in 6%. Of the IM that were investigated with contrast medium, 88.5% showed marked enhancement. It was homogeneous in 88% and heterogenous in 6%. Rim enhancement with central low attenuation was seen in 6%. There was no difference in enhancement characteristics with respect to ADC values or fusion patterns. Peritumoral enhancement was identified in 2.4%.
Magnetic resonance features of muscle metastases are relatively typical and consist of round or oval intramuscular masses with well-defined margins, marked enhancement, low or moderate ADC values, and moderate to high signal intensity on fusion images.
本研究旨在对较大系列的肌内转移瘤（IM）的磁共振成像表现进行分析。
回顾性分析了 2000 年 1 月至 2010 年 1 月间在马丁路德大学放射学数据库中发现的 28 例（207 处转移瘤）患者的资料。根据 IM 的位置，采用了几种不同的扫描方案。在 12 例患者中，使用多回波 SE-EPI 序列获得了弥散加权（DW）图像，并计算了表观弥散系数（ADC）图。此外，手动生成了 DW 与半傅里叶采集单次激发快速自旋回波（HASTE）图像之间的融合图像。
在 T2 加权图像上，97%的 IM 与正常肌肉相比呈高信号，3%呈等至高信号混合。在 T1 加权图像上，91%的 IM 与肌肉组织相比呈均匀等信号，4%呈低信号，5%呈轻度高信号。对 91 个转移瘤进行了 ADC 值计算，范围为 0.99 至 4.00mm2/s（平均值 1.99±0.66）。低信号强度（<1.5）的 ADC 值见于 26%，中信号强度（1.5 至 3.0）见于 68%，高信号强度（>3.0）见于 6%。接受造影剂检查的 IM 中，88.5%有明显强化。88%为均匀强化，6%为不均匀强化。6%有边缘强化伴中央低衰减。ADC 值或融合模式与强化特征无差异。2.4%有瘤周强化。
肌肉转移瘤的磁共振成像特征较为典型，包括边界清楚的圆形或椭圆形肌内肿块，明显强化，ADC 值低或中等，融合图像呈中至高信号。
